Le Chiffre is a fictional character and the main antagonist in Ian Fleming's James Bond novel Casino Royale. On screen Le Chiffre has been portrayed by Peter Lorre in the 1954 television adaptation of the novel for CBS's Climax! television series, by Orson Welles in the 1967 spoof of the novel and Bond film series, and by Mads Mikkelsen in the 2006 film version of Fleming's novel.

In French, le chiffre means "the figure" (i.e. "the number") or "the cipher." Fleming based the character on occultist Aleister Crowley.Le Chiffre, alias "Die Nummer", "Mr. Number", "Herr Ziffer", "Ochiu Spart" and other translations of "The Number" or "The Cipher" in various languages; is the paymaster of the "Syndicat des Ouvriers d'Alsace" (French for "Syndicate of the Alsatian Workmen"), a SMERSH-controlled trade union.

He is first encountered as an inmate of the Dachau displaced persons camp in the U.S. zone of Germany in June 1945 and transferred to Alsace-Lorraine and Strasbourg three months later on a stateless passport. There he adopts the name Le Chiffre because as he claims, he is 'only a number on a passport'. Not much else is really known about Le Chiffre's background or where he comes from, except for educated guesses based on his description.

Casino Royale, Chapter 2: Dossier for MHe is also fluent in French, English, and German with traces of an Occitan accent.

In the novel, he makes a major investment in a string of brothels with money belonging to SMERSH. The investment fails after a bill is signed into law banning prostitution. Le Chiffre then goes to the casino Royale-les-Eaux in an attempt to recover all of his lost funds. There however, Bond bankrupts him in a series of games in Chemin de Fer. Le Chiffre kidnaps Bond's assistant, Vesper Lynd, to lure him into a trap and get his money back. The trap works, and Le Chiffre tortures Bond by striking his testicles with a 3-foot long carpet beater to force him to reveal where he has hidden the money. Upon determining, however, that Bond will not give in to torture, Le Chiffre produces a knife with the implied purpose of castrating Bond. He is interrupted by a SMERSH agent, however, who shoots him between the eyes as punishment for losing the money. The torture Bond suffers at the hands of Le Chiffre briefly upsets 007's confidence in his profession, and he toys with the idea of leaving the service until the novel's conclusion, when a new threat emerges.

Le Chiffre's death is seen by the Soviet government as an embarrassment, which in addition to the death and defeat of Mr. Big in Live and Let Die, leads to the events of From Russia with Love. In the novel SMERSH attempts to get revenge by killing Bond in an elaborate plot that would embarrass the British Secret Service within the intelligence community.